Fluid multi-and logical circuit

ABSTRACT

Disclosed herein in a MULTI-AND fluid logic circuit comprising essentially of a conventional fluid amplifier having a power source, first and second control channels and first and second output channels. The amplifier is provided with biasing means which is associated with one of the control channels and means are associated with the other control channel for producing a control signal which is a function of a predetermined number of external signals. More particularly, this last named means comprises a plurality of aspirators, each having an input nozzle and an exhaust nozzle and each connected to an enclosed manifold which in turn is in fluid communication with the second control channel of the fluid amplifier. The operation is such that the simultaneous presence of a fluid signal in all aspirators creates a sufficient pressure change to switch the fluid stream in the fluid amplifier from the first output channel to the second output channel.

United States Patent n 1 Swartz [111 3,786,838 [451 Jan. 22, 1974 FLUIDMULTl-AND LOGICAL CIRCUIT [75] Inventor: Elmer L. Swartz, Annandale, Va.[73] Assignee: The United States of America as represented by theSecretary of the Army, Washington, DC.

[22] Filed: May 22, 1973 '[21 Appl. No.: 362,720

[52] US. Cl 137/814, 137/8 25 ,13:l /3:l,

[51] Int. Cl. F15c 1/14 [58] Field of Search 137/814, 825, 836, 837;

235/201 R, 201 FS, 201 PF, 201 ME [56] References Cited UNITED STATESPATENTS 3,499,459 3/1970 Swartz 137/836 X 3,442,279 5/1969 Swartz137/836 3,425,431 2/1969 Heskestad 137/836 3,380,655 4/1968 Swartz235/201 PF 3,324,730 6/1967 Bowles.... 235/201 PF 3,191,611 6/1965 Bauer235/201 PF X Primary Examiner-Alan Cohan Assistant Examiner-Ira S.Lazarus Attorney, Agent, or Firm-Edward J. Kelly; Herbert Berl; SaulElbaum [5 7] ABSTRACT Disclosed herein in a MULTI-AND fluid logiccircuit comprising essentially of a conventional fluid amplifier havinga power source, first and second control channels and first and secondoutput channels. The amplifier is provided with biasing means which isassociated with one of the control channels and means are associatedwith the other control channel for producing a 3 Claims, 3 DrawingFigures 1 FLUID MULTI-AND LOGICAL CIRCUIT RIGHTS OF THE GOVERNMENT Theinvention described herein may be manufactured, used and licensed by orfor the United States Government for governmental purposes without thepayment to me of any royalty thereon.

BACKGROUND OF THE INVENTION This invention relates to MULTl-AND fluidlogic devices, and more particularly to a MULTI-AND'fluid logic deviceutilizing only a single fluid amplifier in combination with a manifoldwhich is associated with a plurality of aspirators.

A fluid AND device is such that it must have a signal present at everyinput in order to produce an ANDED output signal. In the prior art, asingle AND device generally combines two input signals to produce theANDED output. Such a device usually combines two fluid amplifiers inwhich the power nozzles of each of the amplifiers consist of the twoinputs and in which one output channel from each of the amplifiers istied together to constitute the ANDED output. If many such signals areto be ANDED, then the outputs of the individual AND units must furtherbe ANDED until there is a single output from the device. Thus, Aschematic device for ANDING eight fluid signals would require the use ofeight separate AND units which would, in turn, require the use ofsixteen fluid amplifiers. In such a circuit arrangement, the outputsignal would be approximately only six percent of the input signalpressure, assuming all input signals are about equal amplitudes.

It is, therefore, a primary object of this invention to provide aMULTI-AND circuit which does not suffer from any of the aforementioneddisadvantages.

Still another object of this invention is to provide a MULTl-AND circuitwhich utilizes only a single fluid amplifier in its construction.

Another object of this invention is to provide a fluid MULTI-AND circuitin which there can be a wide variation in amplitude of each of theseveral input signals.

Yet another object of this invention is to provide a circuit whichutilizes less space and is far simpler and cheaper to constructthan areprior art devices.

SUMMARY OF THE INVENTION Briefly, in accordance with this invention, aMULTI- AND fluid logic circuit is provided which comprises a fluidamplifier having a power source, first and second output channels andfirst and second control channels. Biasing means associated with thefirst control channel is provided for directing the fluid stream intothe first output channel in the absence of a more powerful controlsignal. Means are associated with the second control channel forproducing a control signal to switch the fluid stream whenever apredetermined number of external signals to be ANDED are simultaneouslyprovided. This last named means comprises a plurality of aspirators,each having an input nozzle and an exhaust nozzle and each being influid communication with an enclosed manifold. The manifold is, in turn,in fluid communication with the second control channel. Upon thesimultaneous application of fluid signals in each of the aspirators, asufficient reduction in pressure occurs in the second control channelsuch that the power fluid DESCRIPTION OF THE EMBODIMENT The specificnature of the invention as well as other objects and advantages thereofwill clearly be apparent from the following description and associateddrawings.

FIG. 1 illustrates the fluid flow in the MULTl-AND circuit in theabsence of signals applied to the aspirator channels.

FIG. 2 illustrates the fluid flow with all input signals applied.

FIG. 3 illustrates the fluid flow with all but one input signal applied.

Referring now to FIG. 1, amplifier 10 is provided with power inputnozzle 11 for issuing a stream of fluid into interaction region 14,whereupon the fluid is diverted to either of output channels 12 or 13.Control channels 15 and 16 are provided in fluid communication withinteraction region 14 to provide the appropriate switching area. Biaschannel 17 connects fluid from power nozzle 11 to control channel 15such that under normal flow conditions fluid in power nozzle 11 would bepartially diverted into bias channel 17 and would exit to atmosphere byway of control channel 15. This flow of fluid in bias channel 17 wouldcreate a low pressure region immediately adjacent the left hand portionof interaction region 14 which would in turn cause the main power fluidto be deflected toward the left and to exit, as shown, through outputchannel 13.

Control channel 16, which is located at the right hand side ofinteraction region 14, is in fluid communication with an extendedmanifold region 50. Manifold 50 is provided with a plurality ofaspirator channels 1 through 8 which communicate with a source of powerfluid as well as with atmosphere. More particularly, each aspirator isconnected to manifold 50 by means of a channel 53 which is in fluidcommunication with a channel 51. Channel 51 is provided with an inputnozzle 54 which may be connected to a source of pressurized fluid andwith an exit nozzle 52. The arrangement shown in FIG. 1 assumes that nofluid signals are present near any of the aspirator signal sources 1through 8. Accordingly, manifold 50 is in fluid communication withatmosphere by means of channel 53 and exit nozzle 52. With thisarrangement, the fluid flow in amplifier 10 would be as indicated by thearrow, that is, fluid bias channel 17 would cause the power fluid toexit by way of output channel 13.

Referring now to FIG. 2, this arrangement assumes that each of theaspirator channels 51 is provided with an active source of fluid signal1 through 8. Each of these said fluid signals causes fluid to enter theaspirator channel and to exit by means of exhaust nozzle 52. As fluidexits from exhaust nozzle 52, suction is created in the region ofchannel 53. Each of the aspirators contributes a certain amount ofsuction within the manifold 50 such that the total amount of suctioncreated by the added effect of all eight aspirator channels tends tocreate a low pressure region immediately to the right hand side ofinteraction region 14 and within control channel 16. When the lowpressure in control channel 16 is such that it overcomes the lowpressure within control channel 15, the power fluid is caused to switchfrom outputs of channel 13 and to exit instead through output channel12. Thus, upon the application of all eight signals in all eightaspirator channels, an ANDED output signal is achieved in amplifier bythe presence of power fluid in output channel 12.

FIG. 3 illustrates the situation in which any one aspirator channel,such as channel 3, is not provided with a signal source. In thisillustration, the absence of fluid flow in aspirator channel 3 enablesmanifold 50 to be in fluid communication with atmosphere. This fluidcommunication with atmosphere is sufficient to draw in fluid intomanifold 50 and to thereby counteract the suction created by each of theother aspirator channels. A single aspirator channel which does notcontain a fluid signal will be sufficient to replace enough air intomanifold 50 to void the combined suction effects of each of the otheraspirators. This is true regardless of how many aspirator channels areprovided in communication with the manifold channel. Thus, in theexample of FIG. 3, a sufficient amount of low pressure in controlchannel 16 is not achieved and the power fluid continues to exit throughoutput channel 13 of amplifier 10. It is significant that there can bewide variations in amplitude in each of the eight signal inputpressures, sinceit takes only a very small signal to essentially sealoff atmospheric pressure from manifold 50;

Referring back to FIG. 1, it should be noted that the bias means foramplifier 10 need not necessarily be in the form of a bias channel 17.Alternatively, the bias means can consist of an additional amplifier 30,having inputchannel 31, control channels 32 and 33, and output channels34 and 35. Output channel 35 is provided in fluid communication withcontrol channel 15 of amplifier 10 by means of an extended channelportion 36. Upon the application of appropriate control signals throughamplifier 30 such that fluid is caused to flow through channels 35 and36, the reduced pressure region would again be created in controlchannel 15 which would in turn cause fluid amplifier 10 to be biasedleft wise as shown. Still additional and alternative types of biasingarrangements can be utilized, such as the NOR type. In this type ofbiasing arrangement, the amplifier is biased to the left side when noswitching signal is present in the right control side. A switchingsignal in this case means a reduced pressure. In any case, the amplifier10 should be biased such that output should flow through left outputchannel 13 when the power jet pressure is initially applied and in theabsence of the appropriate number of aspirator signals.

It will thus be apparent that a MULTI-AND device has been illustratedwhich is capable of producing an ANDED output signal whenever apredetermined num ber of input signals are simultaneously applied. Moreimportantly, the device is such that it requires very little space andis extremely simple and easy to construct. The aspirator signals 1through 8 need not be of uniform or identical size or pressure since avery small signal is capable of essentially sealing off atmosphericcommunication with the manifold 50. Additionally, the number ofaspirator signals can be readily and easily added or subtracted to thedevice as desired.

I wish'it to be understood that I do not desire to be limited to theexact details of construction shown and described, for obviousmodifications can be made by a person skilled in the art.

I claim as my invention:

1. A MULTl-AND fluid logic circuit comprising:

a. a fluid amplifier having a power source issuing a fluid stream intoan interaction region, first and second output channels for receivingsaid fluid stream and first and second control channels for directingsaid fluid stream into said output channels;

b. biasing means associated with said first control channel fordirecting said fluid stream into said first output channel in theabsence of a more powerful control signal;

c. means associated with said second control channel for producing acontrol signal for switching said fluid stream into said second outputchannel;

(1. said last named means comprising a plurality of aspirators eachhaving an input nozzle, an exhaust nozzle and a connecting nozzle incommunication with an enclosed manifold, said manifold being in fluidcommunication with said second control channel, whereby the simultaneouspresence of a fluid signal in all of said aspirators creates asufficient pressure reduction to switch said fluid stream from saidfirst output channel to said second output channel.

2. The device of claim 1 wherein said biasing means comprises a biaschannel providing fluid communication between said power source and saidfirst control channel, whereby fluid flowing in said bias channelcreates a low pressure signal in said first control channel.

3. The device of claim 1 wherein said biasing means comprises a secondfluid amplifier having an output channel and fluid communication withsaid first control channel, whereby fluid flow in said output channel ofsaid second fluid amplifier creates a low pressure signal in said firstcontrol channel.

1. A MULTI-AND fluid logic circuit comprising: a. a fluid amplifierhaving a power source issuing a fluid stream into an interaction region,first and second output channels for receiving said fluid stream andfirst and second control channels for directing said fluid stream intosaid output channels; b. biasing Means associated with said firstcontrol channel for directing said fluid stream into said first outputchannel in the absence of a more powerful control signal; c. meansassociated with said second control channel for producing a controlsignal for switching said fluid stream into said second output channel;d. said last named means comprising a plurality of aspirators eachhaving an input nozzle, an exhaust nozzle and a connecting nozzle incommunication with an enclosed manifold, said manifold being in fluidcommunication with said second control channel, whereby the simultaneouspresence of a fluid signal in all of said aspirators creates asufficient pressure reduction to switch said fluid stream from saidfirst output channel to said second output channel.
 2. The device ofclaim 1 wherein said biasing means comprises a bias channel providingfluid communication between said power source and said first controlchannel, whereby fluid flowing in said bias channel creates a lowpressure signal in said first control channel.
 3. The device of claim 1wherein said biasing means comprises a second fluid amplifier having anoutput channel and fluid communication with said first control channel,whereby fluid flow in said output channel of said second fluid amplifiercreates a low pressure signal in said first control channel.